One of the best things about the rise of the smartphone over the past few years is the incredible number of creative ways that companies have come up with to utilize them. We’ve seen thousands of innovative and interesting apps, and more recently some cool secondary gadgets that extend their functionality by interfacing directly with the phone. Take for example the hipKey from a company called Hippih. The device is a motion and proximity sensor that can alert us when our valuable items have been moved, something that can come in very handy when traveling.

The hipKey is a small, half-moon-shaped device that is designed to be attached to a set of keys, your luggage or even a person. When powered on and paired with an iPhone via Bluetooth, it can provide a host of useful functions. At its core, hipKey is meant to alert us to changes to the location of the item it is attached to or help us find that item when it becomes lost. If you attach the device to a set of car keys for example, hipKey will let you know when you’ve left them behind via an alert on your iPhone. Or, if you’re one of those people who can never remember where you left your keys, the hipKey companion app (available for free in the App Store) can activate the device, forcing it to make a loud noise.

The sensor features four distinct modes, each of which is designed to address some specific need. For instance, Alarm Mode is meant to alert the user when the hipKey has moved beyond a certain distance from their smartphone. The distance at which the alarm sounds can be set to short (2-5 meters), medium (15-20 meters) and long (30-50 meters) ranges. In Safe Zone mode, the user can designate a specific place on a map as the “safe” spot, then create a geofence around it at the same preset distances as Alarm mode. If the hipKey moves outside of the zone, it will again automatically trigger alerts. As the name implies, Child Mode attaches the hipKey to a child and sets off alerts if the kid wanders out of range as well, while Motion Mode immediately sets off an alarm if the item that the device is connected to begins to move.The hipKey dongle is roughly 2 inches in diameter, which is at times too large and at others just the right size. I say that because when you attach the device to a carry-on bag, for instance, you barely even notice that it is there. But add it to your keychain and suddenly it feels enormous. But the device packs quite a bit of technology into a relatively small space and for the most part you’ll barely even notice that you have it with you.

When designing the hipKey, Hippih integrated BlueTooth 4.0 technology, which provides better range than previous versions of the protocol while sipping less battery life. The device has a built-in rechargeable battery that I’m told will power the proximity sensor for anywhere from two to four weeks. I tested the device for a period of just over three weeks and I wasn’t able to ever run it out of juice, which bodes well for travelers who want to attach this to their baggage while on the go. I also didn’t notice much of an impact to the battery life of my iPhone while connected to the hipKey either.

As mentioned above, Hippih has developed a companion app for the hipKey that allows the user to program it to their specifications. It is through that app that you can set which mode the device is operating in, adjust the volume of alerts, select the alarm distance and so on. It’ll also tell you the current battery level of the device and allow you to designate your “safe zone.” The app is functional and easy to use – and works nicely on an iPad – but for the most part there isn’t much that is impressive about it.

It should be noted that communication between the iPhone (or iPad) and the hipKey is not just one-way. If you can’t find your iPhone, you can tell the device to send an alert to the phone, causing it to make a chiming noise while also vibrating. The alerts can be heard even if the iPhone is set to silent mode, which can come in very handy when you just can’t seem to remember where you left your iPhone.

For the most part, the hipKey works exactly as advertised. It is a snap to set up and it provides alerts when it moves too far away from the iPhone with which it is paired. I tested the device extensively and it performed flawlessly each time. It is nice to know that it has a solid record of dependability when you’re counting on it to ensure that your bags, keys or child stay safe.

Unfortunately, at the moment the hipKey doesn’t work with any other devices except the iPhone. Android and Windows Phone users will just have to wait to see if Hippih brings the device to those platforms. It seems likely that support will be there eventually – particularly in the case of Android – but for now the proximity sensor only works with Apple devices.

The hipKey carries a price tag of $89.95, which seems a little steep at first glance. But if you consider the level of mobile security, not to mention convenience, that it brings to the table, it comes across as a small price to pay. The perpetually forgetful will appreciate the gentle reminders the device will send them when they walk away without their keys, while worried parents will wonder how they kept track of their little ones without it. Make no mistake, this device is indeed a luxury item, but it is also one that could possibly save you a lot of grief when you need it. Particularly when keeping tabs on your important gear while traveling.

The hipKey is an excellent compliment to any iPhone and surely a gadget travelers will love to have on their side in times of trouble.